Heating feed water



Aug. 3, 1937. N. T. MCKEE 4HEATING FEED WATER Filed April 24, legs 2 Sheets-Shea INVENToR NfS/4L .\1 l., ynvluunlv. 00000000000000 0000000000000 v 0000llllil.

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ATTORNEY Aug. 3, 1937. N. T. McKl-:E 2,083,917

HEATING FEED WATER Filed April 24, 1936 .'2 Sheets-Sheet 2 INVENTOR /VfAL TMS/(15E.

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ATTQRNEY Patented Ang.` 3, 1937 HETING FEED WATER NeaPTIMcKee, Bronxville, N. Y.,"assignor` to The 'Superheater Company, New"York,N. Y.

Application April 24,

theseveral steamfdriven auxiliaries with which 15 thelocomotive is equipped. Heretofore this preheating of theieed-Water hasbeen accomplished by eitherofftvvoH general types yof apparatus, i.` e., by e means of `an injector operated ilargely by engine'exhauist steam when such steam is avail` 9,() able, l'ar-iti operated `by live steam when exhaust steam is notavailable, or by means of a'feed Water heaterof 'either' theA closed or open type, used in` conjunction with some form of mechanical feed pump.. Neither of these general forms oflequip- Se mehtiscompletely `satisfactory from all standpoints becauseiof inherent limitations which render'them in one crmore respects unsuitable for the'vvork they are intended to perform. `For example, 'itfis desirable to preheat the feed Water e 31() going "to"v Athefboiler y"to the maximum possible degreejfbututhis factor in the case of the exhaust steamginjectoi" must be subordinated to the primaryijrequirement 'of securing with the injector 'afdelivery `pressure sufficient to force water to the 35 boiler."` inorderto secure such a delivery pressure under any` set of locomotive operating conditions which "inayj exist, the injector must be designed primailyto" produce pressure and in order to secure this result the injector design does not perflmit the Water tobeheated to a degree which might'jbe"reacl1ed if heating of the Water Were the only iactorvvhichhad to be considered in the des n. fFurtliermore," it is diiicult to secure duninterrupted operation of an ex- "Injector 'when the latter `has todee, neQnigh boiler pressures now in common usegand When unfavorable operating conditionsjexist it is sometimes impossible to secure proper. operation of this type of apparatus. The systems .using pumps and feed Water heatersfalsfo `possess certain limitations of a practical,"natureA which jrenderV them not Wholly desirabltefln addition 'to the undesirable Weight fr necessary in a heater of desired capacity, the o" feedwaterhea'ters are subjectto many practical 1936, serialfNo. vente (o1. 12a- 442i` fdif'cultiesdueto leakage, scaling, relatively heavy Weight' and'otherideiects `which need not `here be discussed Fini fdetail.

The-*present "invention" has for its general purposelthe provision of -`means for'supplying' `preheated feed water which willl retain-the Iadvantages'i'f systemsl heretofore l'developed;While at the vsaine 'time eliminating' to the greatest possible -exten't fthe disadvantages 'inherent 'inl prior systems. The` -'inventin further contemplates the provision of meai-isvvhereby the temperature fftheboiler feed Watermay'b'e heated ito a degree materially`above the temperature 'of the exhaust steam` from the "main engine; such additional healting bei accompli-'shed in a thermally eilicient 4ni-anne Moreispecicallmtthe invention contemplates h'euse of -an injectorcapable o`f`delivering feediwater by theffcond'ensi-ng-jaction of the exhaust fste'amagainst apressure substantial* ly above atmospheric i but materially lower than boiler pressuresaidinjector beingdesigned primarily as a. feed vvater heatingmeans and only vsecondarily -as A'a -pressure `elevating f means. By utilizing `th'ef-"inj ector ini-this` mannerA it `may be 'readily designed to4 "secure the maximum possible heatingreiect from the exhaust steam and iurthermoreitmay'be designed so thatv it vvill operate under the most adverse conditions encountered in locomotive practice,` for example, incases where thetemperatureoi thewater supplied to the injector is relatively high `and ywith exhaust steam being "supplied to'the injector under Widely vary` ing pressures. In accordance 'Withthe invention, water delivered from the injector is supplied to some form of mechanical pumping'means which raises the pressure of thevvater as delivered from the injectorland forces itto the boiler. Preferably such pumping means is steam driven and in case such apparatus is used, the exhaust steam `from the pump driving element is utilized to secure Van additional heating effect. This is accomplished by condensing the exhaust steam from the (pump driving element With the Water deliveredby the injector, this supply of steam being maintained, through the 'use of suitable back pressure meanshnder a pressure materially above atmospheric, and therefore at a higher temperature than the exhaust steamwith; which the feed Water is initially heated in the injector. Bymeansofthe above general arrangement the form foi4 injector"necessary `can be considerably simplified as compared with the ordinary exhaust Steam injector and this relatively `light and simple apparatus can be substituted for the heavy and cumbersome feed water heater now ordinarily employed in conjunction with the boiler feed pump.

Other important advantages with respect to installation, control, etc., are secured through this combination of elements and for a clearer understanding of the invention and the various advantages accruing from its use, reference may best be had to the accompanying diagrammatic drawings of suitable forms of apparatus embodying the invention, and the ensuing detailed description thereof.

In the drawings:

Fig. 1 is a diagrammatic side elevation, partly in section, of apparatus embodying the invention;

Fig. 2 is a view similar to Fig. 1, showing apparatus similar to that shown in Fig. 1 but provided with a different control arrangement; and

Fig. 2a is a plan View of part of one of the controls shown in Fig. 2.

Referring now to Fig. 1 of the drawings, A represents an exhaust steam injectorsupplied through conduit B with feed water which is delivered from the injector through conduit C, surge tank D and conduit E to the pump F, and from the latterthrough conduit G to the boiler check valve (not shown).

The specic details of the injector A form no part of the present invention, but by way of illustration a modified form of the type of exhaust steam injector disclosed in U. S. Patent No. 1,618,- 135, granted to me on February 15, 1927, is illustrated, said injector comprising a main casing I forming a low pressure steam chamber 2 from which steam is delivered to the main steam nozzle 3, the-latter being located in alignment with a water nozzle or cone 4 supplied with water from chamber 5 which is connected by `means of passage 6 with the water supply conduit B. Water valve 1 controls the admission of water to the injector, this valve being opened by means of piston 8 actuated upon the admission of steam thereto through the control pipe 9.

'Ihe steam and water mixture from the water cone 4 enters a combining-tube of usual form (not shown) and passes by wayV of the delivery tube I0 to chamber II, which communicates with the delivery conduit C. The combining tube chamber I2 of the injector communicates by way of valve I3 with the usual overflow outlet I4. Valve I3 is normally held closed'during periods when the injector is operated by means of piston I5, which is in communication with the delivery chamber II, and valve I3 furthermore may be manually closed by means of the control mechanism indicated generally at H and comprising a manually operable member located at the point from which the injector is controlled.

The amount of water delivered by the injector is controlled by longitudinal movement of the main steam nozzle 3, which movement it will be observed will restrict or enlarge the annular opening through which water is delivered from the passage 6 to the water cone 4. Movement of nozzle 3 may be conveniently effected by means of a rotatable eccentric member I6 connected by any form of connection, such as the universally mounted shaft I1, to a main control lever I8, the latter being located at the point of control for the apparatus.

Exhaust steaml for operating the injector when the power plant engine is running and for preheating the feed water is supplied through the exhaust steam pipe I9 by way of the exhaust valve 29 to the main chamber 2 of the injector. Since it is necessary to be able to operate the injector during periods when exhaust steam is not available means are provided for supplying, in lieu of the exhaust steam, live steam at reduced pressure which hereinafter will be referred to as auxiliary steam. The auxiliary steam can be advantageously taken from the high pressure steam pipe 9 throughj a suitable branch 9a which communicates with chamber 2 by way of passage 2|, said .passage being controlled by the automatic or change over valve 22.

In order to secure the uninterrupted operation of the injector, means are provided for automatically opening and closing valves 2l] and 22 in alternation so that chamber 2 may be supplied either with exhaust steam from pipe I9 or with auxiliary live steam from pipe 9. Numerous specic forms of apparatus are known by which this function may be accomplished. For purposes of illustration I have shown a form of apparatus disclosed in detail in U. S. Patent No. 1,870,006,

granted August 2, 1932, on the application of Malcolin -Hard. A brief description of this apparatus follows: Valve 22 is provided with a pistonlike head 22a mounted in cylinder 23, the form of the valve being such that when pressure is present in cylinder 23, valve 22 will be closed by pressure of ysteam admitted to it through branch pipe 9a and when pressure is relieved from cylinder 23, valve 22 will be lifted to open position by the pressure of steam from pipe 9a. Steam is v ladmitted to and exhausted from cylinder 23 through passage 24, the latter being either placed in communication with a zone of low pressure or with a supply of high pressure steam by means of the double-seated relay valve 25 operated by piston 25. The position of piston 26 is in turn controlled by the presence or absence of pressure in cylinder 21 in which steam pressure will be built up by leakage past piston 26, provided that the vent pipe 28 is closed. This vent pipe is controlled by a needle valve 29 operated by diaphragm 30, the latter being placed in communication with the exhaust passages of the main engine through pipe 3 I.

Passage 24 communicates by way of passage 32 with cylinder 33, in which is mounted piston 34, the latter operating on the admission of steam to cylinder 33 to open valve 20 against the action of spring 35 which tends to hold the exhaust valve in closed position. The operation of this part of the apparatus is as follows: If exhaust steam is available for use in the injector, pressure will be transmitted through pipe 3| to diaphragm 39, thereby closing the needle valve 29 and permitting steam pressure to build up in cylinder 21. Pressure in this cylinder will force piston 26 to the position shown, causing valve 25 to close communication between passage 24 and the vent pipe 35 and establish communication between passage 24 and passage 31 leading from the steam supply branch 9a. This permits steam to flow from 31 by way of 24 to cylinder 23 to close the automatic valve 22. At the same time steam under pressure is supplied through passage 32 to piston 34 and the exhaust valve 29 is opened. If the exhaust steam'supply fails due to closure of the engine throttle the release of exhaust steam pressure from diaphragm 30 permits the needle valve to open and vent cylinder 21 through pipe 28, and piston 26 becomes unbalanced and shifts valve 25 to its lower position, cutting off communication between passages 24 and 21 and establishing communication between passage 24 and the vent pipe 36. Pressure is thereby released from cylinder 23 and also from the exhaust valve cylinder 33,

causing the automatic valve 22 to zbe iliftedby steam pressure ifrom branch .9a and :1:.errni1ting-` the exhaust valveto be closed I.byspring 35. The pressure of vthe auxiliary live .steam :passing to chamberZ is reducedbythe throttling .action -of asuitable choke port 38.

`From the above it will be 4evident that either exhauststeamor auxiliary live steam willbesup-` plied tothe injector at all times provided `that operating steam .forthe control mechanismdescribed is supplied'through pipe 9. i

' The admission `of Water to theinjector is..:also controlled through this pipe, while the regulation ofthe amo-unt of Water supplieditoithe:injector is controlled through i the manually .operable 'handle I8.'

Pipe `9 is supplied With steam from 'ithe yboiler frompipe 39 in which is located the control valve 4t. A second pipe 4I, also 4controlled by valve 40, supplies steam to the throttle valve of the driving element of pump F, which has been indicated-as a centrifugal pump driven by a steam turbine. The turbine throttle comprises a conical `val-ve member 42 axially movable to regulate the quantity of Vsteam admitted from pipe 4| tokthe inlet passage 43, said valve member beingconnected by a suitable linkage, indicated generally at, to a floatdb pivotally mountedinthellower part of the main chamber 46 of the tankD. 'Thelbottom of chamber 4E is connected b-y meansfoffconduit -With the suction side of pump F. lSteam exhausted from the pump turbine passes through pipe 4l, which has two branches f41aand 41h. Branch lila, has located therein a baokpressure relief valve 48 which may beset to produce any desired "back pressure in the `exhaust pipe 41, which if exceeded will causevalve 48 to open, thereby permitting the exhaust steam to-passto atmosphere through branch- 41a..

Branch 41h leads to the top-lof the tank-Band supplies steam, under a-maximum pressure determined by the setting of valve 48, to a distributing member 49 from which the exhaust steamiis directed `into the trank through i a plurality lof openings 50.-

The delivery conduit C leading from the-injector is preferably connected to a perforated discharge member 5l located directly under the member -49, member 5l serving to produce a 'fine spray of Water adapted to mingle with and condensevthe steamdischarged through openings `lill. Theftop of the tank'may be made intoasseparate mixing chamber by means of `a baffle 52 yfrom `which the Water discharged from 45l and the condensed steam from 49 mayllow tothe main chamber46.

Assuming that it is desired to supply feed water to the boiler, operation of the apparatus-is as follows: Valve 4l) is opened, admittingsteam to pipes 4l and 9. 'This causes the injector Water valve 'l to be opened and also either the exhaust steam l valve 2li vor theA automatic valve'22tobe opened so that the injector is supplied with Water and either exhaust or auxiliary steam, dependingupon Whetherv or no-t the main engine is in operation. The quantity of Water delivered by theinjector is manually regulated through handle I8 Aand the Water so delivered by the injector passes through spray member 5l to the tank D. If,-When the apparatus is started,v no Water is in the tank D, the turbine throttle va1ve`42 is closedbythe depression of iioat` 45 and the admission of-steam to pipe 4l Will not cause the pump to operate. Continued operation oi the injector will Vrapidly fill chamber 4t, causing float-S45 to `rise and :open

valve "42 and thereby startingv the pump after a predetermined water level-is reached in tank D. The speed of thepump `F Willbe determined by the level of the Water in chamber 46 until valve 42 is fully opened by rise of the Water level in the chamber. Rise of the Water level in chamber 46 beyondzthe point necessary to `fully open valve 42 is preventedyby'making the maximum capacity of thepump greater than the maximum capacity of the injector, so `that withvalve 42 wide open the Waterleveluin chamber 46 Will drop. Such drop will cause the -pumpto sloW down until it is automatically stabilized at a speed causing it to deliver tothe boiler the same amount of water that is ,delivered-tothe tank by the injector, plus the condensate formed in the tank.

As soon as the pump turbine begins to operate, exhaust steam therefrom is delivered under pressure through the exhaust branch 4117 to the mixing chamber above baille 52 and the steamserves to;raise the tempera-ture of the Water delivered by the injec'tortoa valueabovethat possible to secure with exhaust steam from the main engine. Such aresult is possible due to the fact that the pumpturbine is operated against a relatively high back pressure maintained by means of the relief Valvev43., which may be of any suitable form.

The back pressure valve 48 .also enables `the i turbine exhaust tomaintain the surge `tankrunder pressure, which is necessary in order `to supply the .pump with Water under pressure. If the suction side of "the pump were supplied With hot Water from the injector at or near atmospheric pressure, thepump would break its suction due to flashing of acertain amount of the suction Water into steam. i

`'It .will be apparent that `the injector, `pump and tank may be so proportioned that under normal operating conditions the entire exhaust from the pump turbine may be condensed in theheater D and therefore conserved, since the heatfrom this steam is returned lto theboiler inthe ffeed Water.

Under some operating conditions and With certain combinations of pump and injector units, it may happen that the exhaust from the pump is insufficient to keep the pressure in tank D at the desired value. In order to insure a predetermined minimum pressurevalue in tank D, a supply of exhaust steam from some other steamoperated auxiliary, or live steam, may be admitted through the conduit 53. This may be termed auxiliary heating steam. Ii live steam is utilized; conduit 53 may be connected to pipe M. Flow through conduit 53 is controlled by theiregulating valvef54, which is diagrammatically illustrated as `closed by pressure in tank D, acting throughlthe pipe 55, which communicates with chamber 565 above the valve operating piston 5l. Valvei54 is opened by spring 53.

Obviously, .with this arrangement, valve '54 is set so as to be closed by a lower pressure in tank D-than isrequired to` open the relief valve 48. It will thus be seen that the pressure in tank' Dymay `bel'held within a predetermined range, the rminimum value of which is controlled by valve 154 and the maximum value of which is controlled by valve 48. By adjustment of these valves, this pressure range may be altered as desired. i i

,In Fig. 2, a modiiied `arrangement is illustrated inwhichthe general organization is the same as that shown inFi'g.` lgbut in which the regulation of the amountgofieed water supplied by the system isefected `by `man-ual controlerthe output of .the: pump, #coupledA with automatic regulation of the quantity of water delivered by the injector in accordance with the rate of feed of the pump. In'this arrangement the injector A receives water from the supply conduit B and delivers it at elevated pressure through conduit C to the surge tank D. From the surge tank the Water is Withdrawn through conduit E by the pump'F which delivers it to the boiler through conduit G. Steam for operating the pump and the injector is admitted through the supply pipes 39 and 9 and auxiliary live steam may be admitted to the surge tank through the pipe 53. The exhaust steam from the pump may also be maintained under a desired degree of back pressure by means of the valve 48 and delivered under such pressure through the pipe branch 41h.

The" details of 'construction of the injector, pump and surge tank are advantageously the same as previously described in detail in conjunction with Fig. 1 and in the present embodiment are shown in elevation, corresponding parts being correspondingly designated.

The difference in construction represented by the present embodiment, as compared With that f shown in Fig. 1, is that the pump throttle l2 is suitably connected by means of a control rod 60 to-a manually operable regulating hand wheel or the like 6| 'preferably located adjacent to the live steam control valve 40.

The sliding nozzle 3 of the injector, which conrols the amount of Water delivered to and by the injector is connected by means of a linkage consisting of rods 62 and 63 and arm 64 (see Fig. 2a.) to the lever attached to the float 45 in the surge tank D.

As will be readily understood, the general operation of the apparatus will be the same as that previously described in connection with Fig. 1 but in the present instance regulation of the amount of feed Water supplied to the boiler is controlled through the manual regulation of the pump throttle valve 42. Depending upon the rate at which water is withdrawn from the surge tank by the pump F, the nozzle 3 of the injector will be adjusted to automatically correlate the capacity of the injector to the rate of operation of the pump. With this arrangement in order to insure an adequate supply of Water to the pump, the maximum capacity of the pump is made less than the maximum capacity of the injector, so that the injector may at all times be capable of supplying all of the suction water required by the pump.

It Will be understood of course that the pump F should be provided with an overspeed governor, which may be of any of the usual conventional types, in order to prevent racing of the pump in the event that for any reason the action of the injector is interrupted for a period long enough to cause the surge tank to be emptied by the pump.

`From the foregoing description it Will be evident that the embodiment of the invention diagrammatically illustrated herein by Way of example may be widely varied Without departing from the invention, the scope of which is defined in the appended claims.

I claim:

1. Means for supplying preheated feed Water to a boiler comprising an exhaust steam injector of the forcing type for delivering Water under pressure and having means for regulating the amount of water supplied thereto, a steam driven pump having a throttle valve, a conduit for delivering water under pressure from the delivery endofthe injector to the suction end of the pump; manually controlled means for actuating said water regulating means and means for varying the opening of said throttle valve in accordanceA With variations in the rate at which Water is supplied through said conduit by said injector. 2. Means for supplying preheated feed Water t a boiler comprising an exhaust steam injector, ofthe forcing type for delivering water under pressure and a steam driven pump arranged in series, with the injector delivering Water to the pump ata pressure substantially above the pressure of the exhaust steam supplied to the injector, means comprising a part of the injector for determining'the rate at which feed Water is supplied to the injector and means influenced by the rate at which feed Water is supplied by the injector for governing the operation of the pump.

f3. Means for supplying preheated feed Water to a boiler comprising an exhaust steam injector, means for regulating the amount of feed Water supplied to said injector, a mechanically operated pump having a greater maximum capacity than the maximum capacity of the injector, means for`conclucting Water delivered by said injector tothe suction end of said pump, and means for automatically regulating the rate at which said pump operates in accordance With the `rate at which the injector delivers Water to the pump.

4. Means for supplying preheated feed Water to a boiler comprising an exhaust steam injector, of the forcing type, a steam driven pump, a conduit connecting the delivery end of the injector and the suction end of the pump, said conduit including apparatus for condensing steam with water passing through the conduit, and means for maintaining the pressure in said condut at a pressure substantially above that of the exhaust steam vsupplied to the injector and for further heating in said conduit the Water delivered by thefinjector comprising means for conducting exhaust steam from the pump to said apparatus and means for conducting an auxiliary supply of steam to said apparatus when the quantityof exhaust steam from the pump is insulicient to maintain a desired pressure in said conduit.

5. Means for supplying preheated feed Water to a boiler comprising an exhaust steam injector, a steam driven pumping unit, means for conveying Water4 delivered by said injector tothe suction end of said pumping unit, said means including a surge tank, means for maintaining the exhaust steam from said pumping unit at a pressure substantially above atmospheric, means for conveyingv the exhaust steam from said pumping unit to said surge tank, and means controlled by the Water level in said surge tank for controlling the operating rate of said pumping unit.

6. Means for supplying preheated feed water to a boiler comprising an exhaust steam injector, a steam driven pumping unit, a conduit includingy ay surge tank for conveying Water delivered by saidjinjector to the suction end of said pump, a conduit for conveying the exhaust steam from said pumping unit to said surge tank, a second conduit for conducting an auxiliary supply of yheating'steam to said surge tank, a valve in said second conduit responsive to pressure in said tank for limiting the minimum pressure in said tank, and a relief valve for limiting the maximum pressurein said tank.

7. In a power plant having a. boiler and a mainengine, an exhaust steam injector of the forcing type, .means .for supplying feed; water for the boiler to said injector, means for supplying exhaust: steam fromthe enginelto the injector, a boiler feed', pump having greater maxximum capacity` than the maximum capacitjnof the injector, meansi providing a-:closed pressure conduit for delivering heated feedwater under `pressure from the injector to the pump, means `for delivering feed water from the outlet of the pump tothe boiler, means associated withv said Ainjector for. regulating the amount `of. feed water suppliedthereto, .and means forcontrolling the rate of operation, of said pump in response to variations; inthe amount of' water' delivered by said injector. l f

8. In a` power plant. having a boiler andra main engine, an exhaust steam injector ofi the forcing-type, means for supplying feed water for the boiler to said injector, means for supplying exhausts steam from. the engineto the injector, a steam driven boiler feed pump, means providing a closed pressure `conduit forydelivering heated feed water from the injector to the inlet of thepump,` said injector being so constructed as to deliver water at a pressure substantially above the `pressure of theexhauststeam from the engine, said conduit including means for condensing `steam with water passing through the conduit, means for conducting exhaust `steam from said pump to said conduit to be condensed therein, means forconducting an auxiliary supply `of steam `to said conduit to-be condensed therein when the exhaust steam from the p-ump is insufficient` to maintain the pressure in said conduit at a value substantially above that of the pressure of the exhauststeam supplied to the injector, and means for delivering feed water from the outlet of the pump to the boiler.

9. The method of supplying preheated feed water to the boiler of a power .plant having a main engine and a boiler feed pump which consists in heating the boiler feed water by condensing therewith exhaust steam from the main engine, utilizing a part of the energy of the exhaust steam so condensed to elevate the pressure of the feed water to a value above that of the pressure of the exhaust steam, delivering the heated feed water to the boiler feed pump at elevated pressure, pumping the feed water to the boiler, and controlling the amount of water fed to the boiler by regulating the amount of water supplied to the pump due to the condensing action of the exhaust steam.

10. The method of supplying preheated feed water to the boiler of a power plant having an engine and a steam driven pump for the boiler which consists in heating the feed water by condensing therewith exhaust steam from the engine, utilizing a part of the energy of the exhaust steam so condensed to elevate the pressure of the feed Water to a value above atmospheric but materially below boiler pressure, delivering said heated water under pressure to the pump, pumping the heated Water to the boiler, utilizing the exhaust steam from the pump to heat the water at its elevated pressure before it is supplied to the pump and supplying auxiliary live steam to the Water at its elevated pressure to heat it when the exhaust steam supply from the pump is inadequate.

l1. The method of supplying preheated feed water to the boiler of a power plant having a main engine by the aid of an injector and a boiler feed pump, which comprises supplying the feed Water to the injector, heating the feed water in eration? of; the pump in accordance withtherate'` lofnoperationofthezinjector; i i .Y

j `12. .'Iihelniethodyof supplying preheated feed water `to Vthe; boiler cfa power, plant having a 'main enginexbythe aid of .aninjectorand a steam driven boiler feed pump, which comprises :supplythexfeedfwater-to the injector, `heating the feed Ywater Ainrtlie r injectorrby condensing therewithaexhaust stseanufrom` the main; engine, utijlizii-ng.` Ta part of ,the` energy. of; the iexhaust .steam sos-condensedntoelevatethe pressure of the feeds water, toiaxvalue above: that `of the pressure ofr the exhaust: steam, deliveringthe .heated feed water underpressure tothe boiler feed pump, regu- :lating `the amounuiof `feed water'supplied to the injectorxn; accordance withiboiler needs, con-V 'trolling the :rate of operation. of the injector, and condensing-exhaust steamfrom, the pump with therfeed waterwafter it is `delivered from the injector` and before itis `supplied `to the pump.

1-3. The method of supplying preheatedreed` watergzto theboiler .of a power plant having a maim engine land a- :boiler feed pump which; con- .sists i-n `hearing `the boiler feed water` by condensing therewith exhaust` steam `from the main engine, utilizingasubstantialupantnof itheienergyr of the exhaust steam so condensed to create a forcing jet whereby to elevate the pressure of the feed Water to a value substantially above that of the pressure of the exhaust steam, delivering the heated feed water at elevated pressure to the boiler feed pump, thereafter pumping the feed` water to the boiler, and regulating the amount of feed water pumped to the boiler by regulating the amount of water with which said exhaust steam from the main engine is condensed.

14. Apparatus for supplying preheated feed water to the boiler of a locomotive comprising a first forcing means consisting of a mechanical pump adapted to receive feed water at elevated pressure, a delivery conduit for conducting feed water from the pump to the boiler, a second forcing means consisting of an exhaust steam in- `jector of the forcing type, means providing a connection for supplying to said pump feed water delivered from said injector, means for supplying exhaust steam from the locomotive engine to said injector for operation of the injector by exhaust steam when said engine is in operation, said injector delivering feed water preheated by the condensation of said steam at a pressure substantially aboveexhaust steam pressure but below boiler pressure, manually controllable means for regulating the rate atwhich water is delivered by one of said forcing means, and means for automatically correlating the rate at which water is delivered by the other of said forcing means to the rate of delivery of the forcing means which is manually controlled.

15. Apparatus `for supplying preheated feed water to the boiler of a locomotive comprising a first forcing means consisting of a` mechanical pump adapted to receive feed water at elevated pressure, a delivery conduit for conducting feed Water from the pump to the boiler, a second forcing means consisting of an exhaust steam injector of the forcing type, means Vproviding a connection for supplying to said pump feed water delivered from said injector, `means for supplying exhaust steam from the locomotive engine to said injector for operation of the injector by exhau'st steam when said engine vis in operation, said injector delivering feed water preheated by the confdensation of said steam at a pressure substantially above exhaust steam pressure but below boiler pressure, manually controllable means for regulating the rate at which water is delivered by said exhaust steam injector, and means for automatically correlating the rate at which water is delivered by said pump tothe lrate of delivery of said injector.

l16. Apparatus for supplying preheated feed water to the boiler of a locomotive comprising a firstv forcing -means consisting of a mechanical `pump adapted to receive feed water at elevated pressure, afdelivery conduit for conducting feed water from the pump to theV boiler, a second forcing means consisting of an exhaust steam inautomatically correlating the rate at which Water is delivered by said injector to the rate of delivery of said pump. 1

17. In a power plant having a boiler and a main engine, an exhaust steam injector of the forcing type, means for supplying feed Water for the boiler to said injector, means for supplying exhaust steam from the engine to the injector, a boiler feed pump having a maximum capacity less than the maximum capacity of the injector, means providing a closed pressure conduit for delivering heated feed water under pressure from the injector to the pump, means for delivering feed water from the outlet of the pump to the boiler, means associated With said pump for regulating the amount of feed Water delivered thereby and means for controlling the rate of operation of said injector in response to variations in the amount of Water delivered by said pump.

18. Means for supplying preheated feed Water to a boiler comprising an exhaust steam injector, means for regulating the amount of feed water supplied to said injector, a mechanically operated pump having a maximum capacity less than the maximum capacity of the injector, means for conducting Water delivered by said injector to the suction end of said pump, means for conducting Water delivered by said pump to the boiler, manually controllable means for regulating the rate at which water is supplied tov the boiler by said pump, and means for automatically regulating the rate at which said injector operates in accordance with the rate at4 which Water is delivered by said pump.

NEAL T. MCKEE. 

